On March 28-29, the "2024 13th China Cement Industry Summit and TOP100 Award Ceremony" was held in Hangzhou, Zhejiang Province. At the meeting, Gao Changming, senior consultant of China Cement Network, made a brilliant report on the theme of "Personal Views on Carbon Neutrality and New Cement Standards".
First, from the germination of "401 negative" to the carbon neutral standard
, Gao Changming made a thorough and systematic investigation and visit to the cement industry of more than a dozen countries, such as Germany, Denmark, the United States, Japan and Brazil, from the early 1980s to the end of the 1990s. The concept of
"Four Zero One Negative" is the scientific and technological achievements obtained by Gao Changming through deep thinking, analysis, induction and summary in his in-depth investigation of the development history, trend and law of the world cement industry during this period, as well as the recognition of the strategy of sustainable development of the cement industry.
Therefore, it is a long and gradual process from the germination of the concept of "four zero one negative" to the final complete finalization.
"Four zero one negative" means that cement production should strive to achieve zero pollution to the ecological environment, zero consumption of external electricity, zero discharge of waste materials, waste residues and waste water, zero consumption of fossil fuels, and negative growth of all kinds of wastes in the whole society.
Nowadays, the highest comprehensive completion rate of "401 negative" in cement industry is Germany, which is close to 70%, 60% in Northern and Western European countries, 45% in China, 30-35% in South American and Eastern European countries, and 10-20% in North America, Australia, Japan and Korea. Looking back
now, the only defect of the "401 negative" concept put forward by Gao Changming in 1997 was that it did not take into account the problem of carbon dioxide emissions, which was entirely affected by the inadequate level of human scientific and technological development at that time.
However, considering the actual development trend of cement industry at home and abroad in the past 27 or 28 years, it is not difficult to find that the ultimate goal of carbon neutralization and the technical ways to achieve these goals are basically the same.
Gao Changming believes that when a country's "401 negative" comprehensive completion rate reaches 95%, that is, the day when its cement industry carbon neutralization reaches the standard.
China has pledged to achieve carbon neutrality by 2060. According to the reality of China's cement industry, such as the technological level and innovation ability, Gao Changming believes that the carbon neutralization of China's cement industry in 2050 should be a probable event. With the concerted efforts of the
government, industry, enterprises and society, China's building materials industry has made great achievements in green and low-carbon development in recent years. It has become a reality for the cement industry to achieve carbon peak ahead of schedule, and the era of building materials industry moving towards carbon neutrality has arrived.
2. In order to ensure that China's cement industry will achieve carbon neutrality in 2050, China urgently needs to strengthen three important technologies
: 1. On the premise of ensuring the strength, performance and life of cement, use as little clinker as possible and use as much admixture as possible. In order to reduce the proportion of clinker in
cement, the clinker coefficient should be reduced to 0.50, because the unit carbon emission of clinker is the highest, and the carbon dioxide emission per ton of clinker is as high as 900 kg. In order to reduce carbon, clinker must be used as little as possible.
Gao Changming suggested that the cement industry should continue to develop the technology of deep processing of admixtures, the technology of new admixtures for concrete, and give full play to the function of low-carbon admixtures partially replacing high-carbon clinker, which he believed was an effective and important way to reduce carbon.
2、, we should vigorously develop and promote the application of green low-carbon cementitious materials (SCM).
Gao Changming said that it is impossible to achieve carbon neutralization by using calcium carbonate as the main raw material to produce cement. The cement industry must simultaneously develop and utilize aluminate, magnesia, ferrite, etc. As the main raw materials to produce green and low-carbon SCM, so that it is possible to achieve carbon neutralization.
SCM accounts for about 15% -20% of the total consumption of cementitious materials, which is an almost new field.
At present, there are more than ten kinds of SCM with certain effect in application at home and abroad, such as burnt clay cement LC3, low clinker cement LCC, aluminate cement, geological and mineral cement, etc., but the scale is not large, so efforts should be made, investment should be increased, and many technical difficulties should be overcome.
However, China's cognitive level in this respect is not high, and the understanding of the importance of SCM is not enough, which must be paid attention to. In order to
improve the efficiency and reduce the cost of carbon dioxide capture, utilization and storage 3、, special attention should be paid to the development of CCUS.
Gao Changming pointed out that in the foreseeable thirty or fifty years, it is impossible for the cement industry to achieve carbon neutrality without using CCUS at all. It is an inevitable fact that a certain amount of carbon dioxide must be eliminated in the whole process of cement production. What
we can do now is, first of all, to reduce the unit carbon emissions in cement production in an all-round way as far as possible; secondly, to capture and utilize the carbon dioxide efficiently, and develop various ideas and means to utilize the carbon dioxide, which can make the best use of all the carbon dioxide; finally, to store the remaining carbon dioxide.
At present, the carbon dioxide utilization technologies explored by various countries are mainly used in the production of biofuels, ethanol, starch or glucose and other food industries, but these are still in the initial stage, and there is still a long way to go to solve the difficulties of industrial-scale production.
As for other main ways to achieve carbon neutralization, such as burning waste, using alternative fuels, TSR up to 100%, using photovoltaic power, etc., China is successfully promoting, and the effect is increasingly obvious.
3. General recognition and comments on the newly issued GB175-2023 national standard for general Portland cement.
For the recently issued GB175-2023 general Portland cement national standard, Gao Changming said that it further improved the quality of cement in China, promoted the green and low-carbon development of cement industry, fully met the needs of cement users, and also took care of the demands of all aspects, which is an important achievement. He lamented that good things are hard won and we should cherish them.
Gao Changming pointed out that the latest cement standards can be called high-level and high-quality achievements in many aspects, such as advancement, scientificity, safety, accuracy, authority and operability, so the vast number of users, production enterprises and scientific research Institut ions are willing to accept them.
Gao Changming believes that this new standard will play a positive role in summing up experience, drawing lessons, connecting the past with the future, and continuing to move forward.
For this new standard, Gao Changming wants to put forward a small fly in the ointment, that is, to cancel the silicate compliance with PC32.5. He said that PC32.5 cement is actually an excellent variety, especially when China's cement industry is moving towards carbon neutrality, PC32.5 cement can play its strengths.
Because this kind of cement is the closest to green low-carbon cementitious material SCM in terms of carbon reduction, performance and life of Portland cement, and China has long-term experience and advantages in the production, application, research and development of PC32.5 cement.
Germany and the European Union have added two new varieties of 32.5 cement in their recently revised cement standards, while China has cancelled the original and only PC32.5 cement, which is a sense of self-abandonment.
Fortunately, GB175-2023 General Portland Cement National Standard still has the existence of Portland Slag Cement PS32.5, Fly Ash Cement PF32.5 and Pozzolana Cement PP32.5, and the 32.5 grade cement has not been completely cancelled, and the negative impact of PC32.5 cement has been cancelled separately. Apart from the factors related to internationalization, the impact on other aspects is not great and harmless.
Finally, Gao Changming suggested that it would be appropriate for the Cement Bidding Committee to re-accept PC32.5 cement at an appropriate time in the future.
